Quantification of Sedimentation of a Tropical Reservoir Through Satellite Altimetry: A Case Study of Maithon Reservoir

Periodic monitoring of reservoir capacity is essential since it has multi-fold impacts. Loss of storage capacity may affect canal irrigation and increase the magnitude of flooding/drought conditions. The unavailability of bathymetric data may hinder the regular assessment of reservoir storage capacity, though satellite remote sensing data provide effective alternatives. In the present study, Landsat 8 Operational Land Imager (OLI) and Satellite with Argos and AltiKa (SARAL/AltiKa) data were employed to estimate the sedimentation rate (1994–2015) of Maithon Reservoir, Jharkhand, India. The changes in reservoir volume were calculated through a combination of observed water level, SARAL/AltiKa-derived water level, and Landsat 8 OLI-derived water extent. The triple collocation (TC) method was used for uncertainty analysis as the in-situ capacity curve of the reservoir is not available in the public domain. The reduced capacity rate was 7.47 MCM year−1 (with an uncertainty of 0.32 MCM year−1). The present analysis indicates an alarming situation for the live storage capacity of the Maithon Reservoir due to extensive soil erosion and land degradation in the upper catchment of the reservoir. Overall, the techniques adopted in this study can be used as a rapid tool for estimating reservoir sedimentation, especially where the hydrographic survey is limited.